

FOREWORD 



Early in 1941 the Committee on Food and Nutrition (now the Food and 

 Nutrition Board) of the National Research Council transmitted a proposal 

 to the Secretary of Agriculture recommending that studies be undertaken 

 to determine the normal variation in the vitamin A values of milk and 

 butter as affected by seasonal and regional feeding practices, and also the 

 actual variation in the vitamin A values of market butter as sold in the 

 towns and cities in different regions. 



The Secretary forwarded the recommendation to the Bureau of Dairy 

 Industry and the Office of Experiment Stations, Agricultural Research 

 Administration. Representatives of these Department agencies outlined a 

 plan of procedure and presented it to the directors of the State agricultural 

 experiment stations during their annual meeting in Chicago, in November 

 1941, with the result that a Nation-wide cooperative survey was approved. 



The directors of the State experiment stations designated C. H. Bailey, 

 Director of the Minnesota Agricultural Experiment Station, to work with 

 O. E. Reed, Chief of the Bureau of Dairy Industry, and James T. Jardine, 

 Chief of the Office of Experiment Stations, as a committee to develop 

 cooperative plans for the study, to assume over-all administrative direction 

 of the project, and to appoint a Technical Committee to formulate the 

 analytical methods and procedures. 



The Technical Committee was composed of the following scientists: L. A. 

 Maynard, New York (Cornell), chairman; C. J. Koehn, Alabama; H. R. 

 Guilbert, California; F. P. Zscheile, Jr., Indiana; G. W. Snedecor, Iowa; 

 L. S. Palmer, Minnesota; I. L. Hathaway, Nebraska; W. H. Peterson, Wis- 

 consin; and C. A. Cary, Bureau of Dairy Industry. Later, C. A. Cary was made 

 chairman, W. D. Salmon of Alabama succeeded C. J. Koehn, and W. F. 

 Geddes of Minnesota succeeded L. S. Palmer. 



The first responsibility of the Technical Committee was to organize and 

 undertake such cooperative work as was necessary to develop suitable methods 

 for obtaining samples of butter and for determining its carotene and vitamin 

 A content. Meantime, plans were developed and arrangements were made for 

 participation by State experiment stations that were so located as to be able 

 to provide data fairly representative of the butter produced in the United 

 States. 



After a year's cooperative work, the Technical Committee made recom- 

 mendations regarding methods of obtaining butter samples and determining 

 their vitamin A potency. These methods were approved by all agencies 

 participating in the study and, in all essential respects, these were the ones 

 used in the analytical work and in compiling the results. The Technical 

 Committee worked closely with the State leaders throughout the study and 

 also assumed the responsibility for the compilation and evaluation of the data. 



The study itself and the organization necessary to undertake it have been 

 complex and the work has been carried to completion with difficulty under 

 war conditions. The organization, procedures, and results will stand as an 

 example of what can be accomplished by voluntarv cooperation. 



Administrator, Agricultural Research Administration. 



Ill 



